Jetties and Marine Structures

With some 100 km of jetties tested both piles and deck it is a little difficult to show the range of our experience and capability. So we decided to show the two extremes well nearly. We have a library of 50,000 photos from the four corners of the world.

This is a 10,000 tonne off shore structure destined for the South China Sea. In a complex rig such as this one there are large number of collisions of members due to design requirements. Even though assemble programmes usually eliminate 90% the remaining are altered at the fabricators own risk! This being a production platform rig it had gone through 100's of change orders such that in the end we were asked to "put some numbers to the changes".

The next problem was that the launch jetty piles didn't line up with the skids. We tested the jetty and calculated its short fall and subsequently supervised the up grade.
Large savings were made by the fabricator due to our testing efforts.

This jetty is in south Australia, on the other side of the earth and scale of engineering, but equally as challenging. Its nearly a 100 years old and still standing. Part had been burnt down but 900m still remained. Its a recreational jetty with excellent fishing. The main concern here is to quantify the amount of worm attack and target a repair date.

We performed our normal pile tests and were able to show that the jetty was still serviceable and would last.

Another view of the same jetty.

Do repairs work? This one of the major questions arising from any remedial works. This is a propriety wrap system for new timber piles. It stops the splash zone erosion of timber, however it does prevent worm attack. It is possible to see worm attack in raw seismic tests (pulse echo) but it is not reliable. Only full modeling of the pile under test can reveal these infestations.

The old pile in this shot has sheared off at MSL. It is possible to make out the depth of the original pile as then the timber pile was classified and stamped with its length on it. Some may be 60' long (18m). some may be second hand, taken from a deep jetty and re-used.

Timber jetties are more durable than concrete or steel and require relatively little maintenance. The latest methodology for timber piles is not to dress them but place them in their natural state.

Further information is available from us so if you have any questions please contact us at